Bipolar PI MD with GB and DD Coil

[Detectorist#1]

Hi Ahmat,
Извиняюсь, ето моя ошибка. Правилное имя LM393P. Sorry, the right name is LM393P.

[pechkata]

Yes, me and GeoMax have PCB files for this project but they will be posted after serious tests in real fields.

What happened to the tests - 20 days have passed...?

[Detectorist#1]

Hi pechkata,
The boards from China are here. I hope, in next two weeks they will be assembled. The tests will be performed when the weather allows.

[Detectorist#1]

Hi pechkata,
It is very interesting what news you have for this problem -
"I glued 3 pieces of circuit board.
All three work differently.
One of them works like yours."
If only one board works properly - where is the problem?

[pechkata]

Hi pechkata,
The boards from China are here. I hope, in next two weeks they will be assembled. The tests will be performed when the weather allows.

Hello Detectorist#1
We won't see anything, neither boards nor video test...
We're just scratching our fingers on the keyboard...

[GeoMax]

Hello Pechkata,

be patient... Detectorist#1 may not be finished with the board assembly and testing yet. Here's a little preview of what to expect. Each detector (Bipolar PI and TX-Pulse Mode design) has a main board and a power supply board to keep the entire design compact and fit into a standard Hammond case.

[karakus]

PCBs look nice I'm waiting to build the circuit

[Prince Zhakata]

Hi Prince Zhakata,
And when the target changes the RX answer, this automatic Ground balance what will do?

Last time when i designed a metal detector without ground balance, hey it was like what...
I can start to detect the ground an a meter with my search rised imagine if put it about 2 to 3 inches on the ground to search it was like Searching with a huge metal on the search head ot like i incase the coil in metal cover just the ground iron mineralised soil.

[Prince Zhakata]

Automatic ground balance traces ground mineraization changes and cancels it automatically leaving targets signals detection without huge back ground, ground mineraization noise to some limits.

[Detectorist#1]

I am now doing intensive tests of this design on a bench. Unfortunately, my hope for good recognition of Fe/Non-Fe targets with DD coil is failing. The answer depends on the orientation of the target. Perhaps when using a PI detector, the only sure method for discrimination is the shovel. The EFE cancelation and GB rests as advantages of this project for now.

[eduardo1979]

Hello Detectorist#1. You're telling the truth. This behavior is typical of PI detectors. I also tried my Bipolar detector that Carl published in his book ITMD3 and realized that FE/NOFE discrimination depends on the target position. I think the best way to achieve good discrimination would be to build a Hybrid detector, since VLF detectors have reached their peak and there's little left to explore. I remember you published a schematic of a Hybrid detector. Did you ever try it? I've never tried a Hybrid, but I'm curious.

[Detectorist#1]

Hi eduardo 1979,
Reliable Fe/nonFe discrimination maybe needs additional magnetometry sensing in VLF and PI designs. My old design (8 years old) with one big outside TX coil and two inside RX coils with differential first RX stage, make true reliable Fe target recognition but the sensitivity for Fe targets is not very good. Beer bottle cap is recognized only from 15cm with 10cm distance between two RX coils. In "Fe recognition" mode, the TX pulses are disabled and the two RX coils works as magnetometer. My "Hobby Hybrid MD design" from February this year maybe also will not do reliable Fe/nonFe recognition - this project also uses PI TX-ON analysis of RX signals as criteria.

[AhmatAhmatov1959]

I am now doing intensive tests of this design on a bench. Unfortunately, my hope for good recognition of Fe/Non-Fe targets with DD coil is failing (this is my first design with DD coil). The answer depends on the orientation of the target. Perhaps when using a PI detector, the only sure method for discrimination is the shovel. The EFE cancelation and GB rests as advantages of this project for now.

Hello. I made printed circuit boards for 2sk116 transistors, the Chinese wrote that they were from Japan. But their capacity turned out to be 4500pf, also 20 pcs 34063 bought from different manufacturers turned out to be defective. Now I'm waiting for a parcel from China How does the metal detector react to gold. If GB works, then that's already good.

[eduardo1979]

Hello Detectorist #1. So, we'd need to find out what kind of technology the Golden Mask Altus and AKA Smart Pulse hybrid metal detectors use to make a detector similar to them. I've only seen them in action in videos; I've never been able to test one.

[Riss]

both are not hybrid detectors, but "gender" VLF . here is an exact analogy - https://www.youtube.com/watch?v=zxGWaOTaocs . From all perspectives, the Italian woman is a woman (she has female breasts). From all perspectives, the "Algerian woman" is a man. Welcome to the time of the new order (Novus ordo seclorum) - the inscription under the pyramid on a one dollar bill...